Mr. S. S. Buckman on Jurassic Brachiopoda. 3D3 



valve with a broad shallow sulcus; the beak without definite 

 ridges ; the foramen round. 



liemarks. — Topotypes kindly given to me some years ago 

 by Mr. E. Walford, F.G.S., show that this form is really a 

 Terebratuloid, and has not the septum nor the form of beak- 

 ridges and foramen characteristic of Jurassic Dallininse. It 

 is a hon!oeomor[)h of Orthotoma toarciensis (= T. Lycetti^ 

 E.-Deslong.), which does show these features, and, moreover, 

 occurs nearly at the same horizon, so that mistake is easy. 



The sulcate dorsal valve suggests that the present species 

 is an early form of the genus Pseudoglossothyris, a genus 

 which is in character allied to the Nucleataj, and is not one 

 of the Biplicatfe. Davidson's figs. 20, 21 of pi. vii. vol. i., 

 cotypes of T. Lycetli, probably belong to the present species ; 

 at any rate they must be removed from Oraithella Lycetli 

 (Dav.). 



Ttvehratula ( Waldiicimia, ZtiUeria) perforata^ auct. 



Certain species which have been known by the trivial 

 nume perforata, coupled with the generic names given above, 

 would perhaps be better assigned provisionally to Oraithella 

 ihau to Zeilleria. Probably they belong to neither genus, 

 but require a new designation; the same remark applies 

 to the species described above, assigned to Omithella : t!iis 

 point, however, cannot be settled till tliere be information 

 concerning internal details. At present, vice Waldheiiaia 

 discarded through prior use, there are the generic names Orai- 

 thella and Zeilleria for these forms. Tliey are not Microthyrisj 

 and certainly not Orthotoma, nor Cincta. 



Eudes-Deslongcliamps used the natne '' Terehratula per- 

 forata, Piette," although he admitted that the designation 

 2\ perforata had already been applied to a Tertiary siieli. 

 !So Piette's name must fall. The same author says that 

 he has refigured, in his pi. xi. fig. 1, Martin's type of 

 T. strangulata as T. jje>forata. If so, Martin's figure is 

 bad. But taking Eudes-Deslongchamps's word for it, then 

 T. strangulata, Martin, is a much larger form than what is 

 known in England as T. perforata. 



But our Lower Lias shell had been named long before 

 Piette or Martin wrote; for it is the type of d'Orbigny's 

 T. sarthacensis. Why this was overlooked by Davidson, 

 Deslongchamps, and others is probably because d'Orbignj 

 placed the species in his Toarcian, and also gave a reference 

 which caused confusion. He quoted T. ornithocephala, Sow., 

 pi. ci. fig. 5, which in our English work appears wrong. 



